The present invention relates in general to computer networks and, more particularly, to a method and system for domain mapping of a network.
Network security products such as intrusion detection systems (ID systems) and firewalls can use a passive filtering technique to detect policy violations and patterns of misuse upon networks to which the Security products are coupled. The passive filtering technique usually comprises monitoring traffic upon the network for packets of data. A signature analysis or pattern matching algorithm is used upon the packets, wherein the packets are compared to xe2x80x9cattack signaturesxe2x80x9d, or signatures of known policy violations or patterns of misuse.
In order to properly detect policy violations and patterns of misuse, security products often must place the packets of data in contexts relevant to such connection criteria as space, time, and event. Space is usually defined in terms of a source-destination connection at the port level. Time is defined as the amount of time to continue associating packets for the type of connection defined by the source-destination connection. Event is defined as a type of connection, which in turn defines the types of policy and misuse signatures that can occur with each packet. As the size of a network expands, there are greater numbers of connections which leads to greater numbers of lookups and comparisons that must be performed by the Security product.
Two problems are associated with conventional security products. First, conventional security products have insufficient information to. self-configure for reliable detection of policy violations and patterns of misuse. For example, conventional security products have no mechanism to reliably ascertain network information of the network to which the security product is coupled. This leads to such disadvantages such as being unable to accurately predict the effect of a particular packet upon a destination device. Furthermore, a conventional security product has no mechanism to ascertain the network topology and thus cannot predict if a certain packet will reach its intended destination. Such a lack of network information compromises the security product""s ability to detect such attacks such as insertion attacks, evasion attacks and denial of service attacks. Some of these problems with conventional security products are documented by Ptacek and Newsham, Insertion, Evasion, and Denial of Service: Eluding Network Intrusion Detection, Secure Networks Incorporated, January 1998.
A second problem associated with conventional security products is the result of scarcity of processor and memory resources. Conventional security products may begin to drop packets and shut down certain tasks in an unpredictable fashion once the system depletes its memory or processor resources. As the size of a network grows, such a failure becomes more likely, as the greater the number of connections onto the network requires a greater number of lookups and comparisons performed by the Security product. Additionally, an increase in number and complexity of the types of misuse the security product is required to detect can further degrade performance. An increase in traffic flow further drains a security product""s resources. For example, conventional ID systems cannot operate effectively at high network bandwidth utilization.
Some conventional systems have attempted to achieve performance gains by decreasing the number of misuse signatures the security product monitors. Fewer signatures translate into fewer memory comparisons for each packet that flows through the security product. However, such a solution makes a network more vulnerable to attacks.
Other conventional systems rely on the user to enumerate the network information, such as the types of operating systems and applications running on the protected network. These systems then disable certain misuse signatures accordingly.
Such a conventional solution, however, introduces its own problems. For example, if the user provides an inaccurate assessment of the network, then incorrect signatures may be disabled, meaning that undetected policy violations and network attacks are possible. Additionally, networks are rarely stable environments and the addition or deletion of devices or services can make the original network information supplied by the user inaccurate.
A further disadvantage of such conventional security products is that they are not designed to function in an environment wherein the traffic exceeds their memory or processor capacity. Such conventional systems, when confronted with traffic that exceeds their capacity, may start dropping packets and degrade performance in an unpredictable fashion. This can lead to an unknown security posture or profile, which can leave a network more vulnerable to undetected attacks.
Therefore, a need has arisen for a method and system that provides a centralized domain mapping of network device information with minimized acquisition overhead and rapid availability to queries from network devices, including network security devices.
A further need exists for a method and system that provides a centralized domain mapping of network device information available for querying by network devices regardless of the capability of the querying network devices to independently acquire network device information.
In accordance with the present invention, a domain mapping method and system is disclosed that provides significant advantages over conventional methods and systems for providing network device information for use by network devices, such as network security devices. A domain mapping device interfaces with plural network devices through the network to receive and store network information from one or more of the network devices, and to provide the network information to one or more network devices upon receiving a query.
More specifically, the domain mapping device includes an acquisition engine for acquiring the network information, a hypercube storage for storing the network information, and a query engine for responding to queries from network devices for the network information. The acquisition engine can acquire network information through active capture, passive capture, polling, or, in cooperation with a network device, through pushing of the network information from the network device. The hypercube storage provides a dimensional, highly indexed data store with a compact footprint and superior update and query performance characteristics. The query engine supports network device queries of network information, including device type, services, operating system and vulnerability data.
One technical advantage of the present invention is that it provides a centralized source of network information that reduces data acquisition overhead and the time needed to obtain network information from network devices. The reduced overhead and time associated with obtaining network information, in turn, supports a more scalable adaptive network security solution.
Another technical advantage of the present invention is that the centralized storage of network information supports access by network devices to all types of network information independent of the network devices"" capability to acquire such data. For instance, network devices that include only passive data sampling capabilities could query the domain mapping device to obtain data available only through active scans. Further, network devices that lack data acquisition capabilities can obtain otherwise unavailable network information from the domain mapping device.
It is a further technical advantage of the present invention that it allows devices coupled to the network auto-configure based upon the network information.
It is an additional technical advantage of the present invention that it allows devices to adapt configurations according to a changing network environment, as reflected in changing network information.
It is another technical advantage that the present invention reduces network overhead associated with network information acquisition because it represents a centralized depository of the network information.